FR2976173A1 - EMBARCATED OPTICAL MEANS FOR BIMODAL DIAGNOSTIC PROBE WITH OPTICAL AND ULTRASONIC IMAGING - Google Patents

Abstract

The invention relates to a device (40) for a bimodal diagnosis probe (1) with optical and ultrasonic imaging, the probe comprising a main body (10) carrying at its front end an ultrasonic transducer (12). The device comprises a shell (41), illumination means (72a) mounted on the front end of the shell so as to provide illumination on the outside thereof, as well as collection or detection means (72b) mounted on this front end of the shell so as to ensure the collection or detection of an optical signal produced externally to said shell. According to the invention, the shell comprises fixing means (80, 82) allowing its reversible assembly around the main body (10) of the probe, with the illumination means and collection or detection means (72a, 72b). mounted on this hull.

Description

TECHNICAL FIELD The present invention relates to the field of optical and ultrasonic bimodal diagnostic probes with optical and ultrasonic imaging. BACKGROUND OF THE INVENTION It particularly concerns endorectal bimodal probes for the diagnosis of prostate cancer. The invention may also relate to vaginal probes, or may be employed for any other diagnosis that may require optical imaging and ultrasound imaging. STATE OF THE PRIOR ART Bimodal probes with optical and ultrasonic imaging have been recently developed, particularly in the field of the detection of prostate cancer. An exemplary embodiment is described in the document "Bimodal Ultrasound and Fluorescence Approach for Prostate Cancer Diagnosis", Journal of Biomedical Optics 14 (6), 2009). This type of probe proves to be efficient because of the complementarity of the two modalities, optical imaging being capable of providing functional information with a good contrast, while ultrasonic imaging provides morphological information with good resolution. Thus, in the early diagnosis of certain pathologies, the approach consists, by means of optical and ultrasound measurements, of making a first localization of the potential tumors, in order then to guide a biopsy tool intended to take a tissue sample from the suspect area or zones. An analysis of these tissues under a microscope subsequently makes it possible to confirm or not their tumor nature. If such probes are completely satisfactory in the features they provide, their design remains to be optimized. In particular, access to optical equipment can be complicated, and require the intervention of a specialized technician to make repairs and / or equipment changes. In addition, it complicates the manufacture of such probes. DISCLOSURE OF THE INVENTION The object of the invention is therefore to remedy at least partially the disadvantages mentioned above, relating to the embodiments of the prior art. To do this, the invention firstly relates to a device for bimodal diagnostic probe with optical and ultrasonic imaging, this probe being intended to comprise a main body carrying at its front end at least one ultrasonic transducer. The device comprises a shell extending in a longitudinal direction between a rear end and a front end intended to form at least partly the front end of the probe 3, this device also comprising illumination means mounted on the end front of the shell so as to provide illumination outside thereof, and collection or detection means mounted on the front end of the shell so as to ensure the collection or detection of a signal optical produced externally to the hull. According to the invention, the shell comprises fixing means allowing its reversible assembly around the main body of the probe, with the illumination means and collection or detection means mounted on this shell. The invention is therefore remarkable in that it provides a removable shell with embedded optical means, which simplifies the design of the bimodal probe on which the device is intended to be assembled. Indeed, repairs and / or changes of optical equipment on board the hull can be initiated simply by dismantling the same hull of the probe, which provides direct access to optical equipment, without having to intervene on the acoustic means remaining as for them stationed on the probe. These operations can therefore be performed easily and quickly, without the intervention of a specialized technician. The simplified design of the present invention also facilitates the manufacture of the bimodal probe, whose acoustic means and optical means can be perfectly dissociated. For example, the optical means can be easily implanted on their associated shell, for example by insertion and / or bonding. Moreover, thanks to this design, the cleaning, disinfection and sterilization phases of the probe can be implemented easily, by dismantling the shells / optical embedded means. Finally, it is indicated that the reversible fixing means may be of any design known to those skilled in the art. By way of example, it may be an assembly by interlocking, wedging, clipping, screwing, etc. Preferably, said illumination means are associated with a first wiring, said collection or detection means are associated with a second wiring, and said first and second wiring run longitudinally along said shell, from said front end of the cable. hull, at least up to its rear end. Preferably, these wirings are also mounted on the shell, all along it. Therefore, they also accompany the hull when it is mounted on the probe around the main body, and also during disassembly.

These wirings may be optical or electrical in nature, depending on the design adopted for the illumination means and the collection or detection means mounted on the front end of the shell.

In this regard, it is noted that the illumination means are intended to produce light.

It may for example be a laser diode, or an LED or a similar element. When one of the elements of this type is retained to form all or part of the illumination means, it is mounted directly to the front end of the shell. Its associated wiring then corresponds to electrical wiring, to connect this element to a source of electrical energy. Alternatively, all or part of the illumination means can be made using the end of an optical fiber, called optical excitation fiber, which then constitutes said associated wiring. In such a case, this optical excitation fiber travels along the shell to then join a distant light source, which can be pulsed or continuous. As regards the detection means, they are intended to detect light, that is to say to detect an optical signal. It may for example be a photodiode, a matrix optical sensor, or any other similar element. When one of the elements of this type is retained to form all or part of the detection means, it is mounted directly to the front end of the shell. Its associated wiring then corresponds to electrical wiring, to connect this element to a source of electrical energy. Alternatively, collecting means capable of collecting light can be retained for conveying it to remote detection means, for example of the type mentioned above. It may then be the end of an optical fiber, the fiber then constituting said associated wiring, allowing the routing of the optical signal to the remote detection means. The optical fiber may nevertheless be replaced by any other light guide deemed appropriate for those skilled in the art, without departing from the scope of the invention. Preferably, as mentioned above, said first wiring comprises at least a first optical fiber whose front end, mounted on the front end of the shell, forms said illumination means, and said second wiring comprises at least one second optical fiber whose front end, mounted on the front end of the shell, forms said collection means. Even more preferentially, said first wiring comprises a plurality of first optical fibers, each of the front ends of which forms illumination means, said second wiring comprises a plurality of second optical fibers, each of the front ends of which forms collection means, the front ends first and second optical fibers on at least one curved line, and preferably only one, forming a plane.

In addition, for optimum performance, the leading ends of the first and second optical fibers are preferably arranged alternately on a curved line, which is preferably an arc of a circle.

Moreover, the angular difference between the front end of any first fiber and each of the front ends of the two directly consecutive second fibers is between 5 ° and 25 °, preferably between 10 and 20 °, and is more preferably of the order of 15 °. These values, contrasting widely with those usually retained in the prior art, significantly improve the collection of the optical signal. The performance of the probe is therefore substantially increased.

Preferably, said illumination means and said collection or detection means are flush with the outer surface of the shell. The absence of protuberance prevents lesions on the tissues against which the probe is intended to be applied. Alternatively, these means could be set back from the outer surface of the shell, while providing for filling the remaining orifice of a transparent material, translucent or diffusing, so that the front end of the shell has the least asperities possible. The invention also relates to a bimodal diagnostic probe with optical and ultrasonic imaging, comprising a main body carrying at its front end at least one ultrasonic transducer, said probe further comprising at least one device as described above, whose shell carrying said illumination means and collection or detection means is reversibly assembled around said main body.

According to a preferred embodiment, the bimodal probe comprises two devices, with the two shells 7 arranged symmetrically in a plane passing through a longitudinal axis of the probe. This design with two shells makes it easier to install the optical means on these same shells, for example a provision means for receiving the optical means directly on the inner surface of these shells. Of course, this solution with two complementary "half-shells" also facilitates the repair and / or change operations of optical equipment embedded on the hull. Preferably, each half-shell is generally concave, the concavity being oriented towards the longitudinal axis of the probe. Preferably, the two shells together form an envelope all around the probe main body, and at their front ends, these two shells define a space filled by said at least one ultrasonic transducer. Therefore, with this design, the shells define almost all the part of the probe intended to be introduced into the human body when carrying out the diagnosis, with the exception of the part covering the acoustic means. Moreover, alternatively, these shells could also cover said at least one ultrasonic transducer, provided they are transparent to ultrasound, without departing from the scope of the invention. According to another embodiment envisaged, the bimodal probe is equipped only with a single one-piece shell, which therefore extends over 360 °. The cleaning and sterilization operations are simplified. In addition, with the one-piece shell, the probe is more rigid. Preferably, for the two-shell solution, the bimodal probe also comprises, at the interfaces between the shells, a filling material for these interfaces. This makes it easier to sterilize the probe, disassemble its hulls means Naturally, this biocompatible material, silicone type without necessarily embedded optics. filler / elastomer, is retained so as not to overly constrain subsequent disassembly of the hulls of the probe. Preferably, the bimodal probe also comprises a grip handle from which the main body extends forward, said handle having one or more grooves on its outer surface, receiving the first and second wiring from the rear end the hull of each device.

Finally, it is noted that the probe is preferably an endorectal probe for the diagnosis of prostate cancer. Alternatively, it may be a vaginal probe. The invention also relates to a method of manufacturing a bimodal probe as described above, comprising the following steps: equipping the shell of each device with its illumination means and collection or detection means; and then reversibly assembling each device around the main body of the probe. The term manufacture is here to be considered in a broad sense, since it concerns not only the manufacture of such a bimodal probe, but also its repair requiring the implementation of the two steps mentioned below, and also the transformation of a ultrasonic probe in a bimodal probe, always by implementing the two steps mentioned below. In the latter case of the transformation of an ultrasound imaging probe into a bimodal probe according to the invention, a first step may consist in removing the original hull of the ultrasound imaging probe. Other advantages and features of the invention will become apparent in the detailed non-limiting description below. BRIEF DESCRIPTION OF THE DRAWINGS This description will be made with reference to the appended drawings among which; FIG. 1 represents a perspective view of a bimodal diagnostic probe according to a preferred embodiment of the present invention; FIG. 2 is an exploded view of that shown in FIG. 1; FIG. 3 represents a side view of the probe shown in the preceding figures, coupled to an imaging system; - Figure 4 shows a longitudinal section of one of the two removable devices with shell equipped with optical means, provided on the probe shown in the preceding figures; Figure 5 shows an exploded perspective view of a front portion of the probe shown in the preceding figures; FIG. 6 represents a sectional view taken along the line VI-VI of FIG. 4; FIG. 7 represents a view from above of the probe shown in the preceding figures; FIG. 8 is a schematic side view showing the arrangement of the optical means on the front end of the shell shown in FIGS. 4 and 5; - Figure 9 shows a schematic view of the mounting of the two removable devices with shell equipped with optical means on the probe; and Figure 10 is a schematic perspective view of the probe shown in the preceding figures, on which a biopsy tool is mounted for taking a tissue sample. DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS First of all with reference to FIGS. 1 to 3, an endorectal probe 1 may be seen according to a preferred embodiment of the present invention. This diagnostic probe is bimodal in that it is optical imaging and ultrasound imaging. It comprises a gripping handle 2 of elongate shape, with axis 4 defining the longitudinal direction of the probe. The handle 2 is extended forward, in the direction of the axis 4, by an insertion portion 6 intended to be inserted into the anatomical region to be investigated. The introduction part 6 thus has a smooth outer surface 8, essentially formed by two removable shells with onboard optical means, which will be explained below. Internally, this insertion portion 6 is formed by an elongated main body 10 of substantially cylindrical shape with axis 4. At its rear end, the main body 10 is carried by the handle 2, while its front end carries means acoustic 12, in the form of one or more ultrasonic transducers covered at the front by a protection 14 of silicone-type material forming part of said smooth outer surface 8. This protection 14 is naturally ultrasonic transparent, biocompatible, and ensures the tightness of the probe. The ultrasonic transducer (s) may be of linear or matrix form, with flat, convex or concave surface geometry. In the preferred embodiment shown, the transducer is a linear array of convex surface geometry, providing a sectorial viewing angle. Indeed, the transducer 14 here takes a global form of half-disk whose plane face is arranged orthogonal to the axis 4, in the direction of the rear of the probe.

An electrical wiring 16 is connected to the transducer 12 and travels through the main body 6, then through the handle 2 to exit at a rear end thereof. The electrical wiring 16 is then connected to an ultrasound imaging system 20, shown in FIG. 3. It is noted that one or more multiplexing electronics modules may be disposed between the transducers 12 and the control system. 20, in order to reduce the number of cables connecting the wiring 16. These modules can be located either in the main body 10 or in the handle 2, without departing from the scope of the invention. As mentioned above, the probe is equipped with two devices each taking the form of a removable shell carrying optical means. These devices 40 will now be detailed with reference to FIGS. 4 to 7. They are arranged around the main body 4 symmetrically along a longitudinal plane passing through the axis 4. Each of these two devices 40 has a hull 41 of which the central portion 42 runs along the main probe body 10. This central portion 42 is cylindrical, with an axis parallel to the axis 4. The cross section of this portion 42 takes the overall shape of a C whose interior is oriented toward the main probe body 10, and the outside of which forms a part of the smooth outer surface 8. More specifically, the inside of the C has a flat portion 44 intended to be in plane contact with a corresponding flat surface 46 of the main body of probe 10, as is best seen in Figures 5 and 6. In addition, the inner faces 50 of the two ends of the C cooperate with cylindrical complementary surfaces 52 of circular section provided s and ur the main body of probe 10, between the two flat surfaces 46. These forms cooperations 14 to correctly orient the hulls 41 relative to the main body of probe 10. At the front, the hull 41 integrates an element d ' front end 56 in overall disc shape, slightly curved outwardly, and intended to contact one of the two lateral sides of the transducer 12. The axis of this disc is orthogonal to the axis 4. When the two shells 41 are assembled on the probe, the two front end members 56 and the transducer 12 together define a forward probe end in the general shape of a sphere, possibly truncated, or a cylinder of axis orthogonal to the axis 4. rear, the shell 41 includes a rear end member 58 which flares to a flat rear end surface 60, orthogonal to the axis 4. This surface 60 is intended to be in plane contact with a complementary surface 62 planned on u an enlarged base 64 of the main probe body 10, mounted at the front end of the handle 2. The elements 42, 56, 58 of the shell 41 are preferably made in one piece, preferably in a plastic material of the type polyurethane, also biocompatible and sealing the probe. One of the peculiarities of the present invention resides in the fact that each shell 41 is equipped with embedded optical means, here constituted by optical fibers running along the shell, along the axis 4. This is all about firstly a first wiring comprising a plurality of first optical fibers 70a, whose front ends 72a each form illumination means for providing illumination outside the probe, being mounted on the front periphery of the Element 56.

It is also a second wiring comprising a plurality of second optical fibers 70b, whose front ends 72b each form collection means for collecting an optical signal produced outside the probe, by the bias of the first optical fibers 70a above. These front ends 72b are also mounted on the front periphery of the element 56. By way of indication, the fibers 70a, called the excitation optical fibers, have a sheathed diameter of the order of 155 μm, whereas the fibers 70b, said detection fibers have a sheathed diameter of the order of 2.1 mm. In the preferred embodiment shown, each shell 41 is equipped with three first optical fibers 70a, as well as two second optical fibers 70b. All the front ends 70b, 72b of the optical fibers are flush with the outer surface 8 of the shell 41, in order to avoid lesions on the tissues against which the probe is intended to be applied.

To do this, these front ends 70b, 72b pass through the thickness of the element 56, to open the probe in the direction of the front, as can be seen in FIG. 5. The fibers 70a, 70b therefore extend from the front end of the shell 41, where they constitute the illumination means 72a and the collection means 72b, and then travel backwards along the inner surface of the shell, in a groove 76 made on the flat portion 44, as shown in Figure 6. This groove 76 correctly guides the optical fibers 70a, 70b, and facilitate their implementation and possible replacement. These fibers extend beyond the rear end of the shell 41, from which they are housed in a sheath 78. This sheath is inserted into a longitudinal groove 79 formed on the outer surface of the handle 2, for then to be connected to an optical imaging system 81 shown schematically in Figure 3, incorporating a pulsed or continuous light source. This connection can be made using quick couplers. Each shell 41 has the particularity of being able to be reversibly assembled around the main probe body 10, with its onboard optical equipment. To do this, it is equipped with appropriate fastening means, here comprising lugs 80 carried by the front end member 56. More specifically, the element 56 carries two lugs 80 diametrically opposed, each intended to be inserted into a notch 82 provided on the outer casing of the transducer 12. In fact, each of the two notches 82 is provided to receive two lugs 80 side-by-side, respectively belonging to the two shells 41. The contact obtained between the two lugs housed in a notch, combined with the contacts of each of these 17 pins with the side flanks of the notch, allow the retention of the lugs within this notch. In addition, the planar contact at the rear end of the shells, between the complementary surfaces 60, 62, makes it possible to block the shells with respect to the main probe body. In this respect, the reversible mounting of the shells 41 around the main probe body 10 can therefore be likened to clipping, by inserting the lugs into their respective notches. When they are assembled on the probe, the shells 41 form an envelope all around the main probe body 10. This envelope is made by the two central parts 42, as well as by the two rear end elements 58. On the other hand, these shells 41 define between the two front end elements 56 a space filled by the transducer 12, as can be seen in particular in FIG. 7. In this same figure, junction interfaces can be seen between the two shells, referenced 86 In order to obtain an outer surface 8 that is as smooth as possible, the grooves created at these interfaces are filled with a filling material. This makes it easier to sterilize the probe, without necessarily disassembling its shells with embedded optical means. Naturally, this biocompatible filling material, of the silicone / elastomer type, is retained so as not to unduly constrain subsequent disassembly of the shells of the probe, for example made by exerting a separating force by means of points inserted into dedicated orifices 88, formed at the interfaces 86 as can be seen in FIG. 7. This filling material is also applied to the interfaces between the shells and the ultrasonic transducer. Referring now to FIG. 8, it can be seen that on each shell, the front ends 72a, 72b of the optical fibers 70a, 70b are arranged alternately along a circular arc 90 of center 89, this circular arc 90, of diameter similar to that of the front end member 56 traversed by the front ends 72a, 72b of the fibers, forming a plane parallel to the axis 4. When the shells are assembled, the two arches of 90 circle are found arranged parallel to both sides of the transducer and the longitudinal axis 4. Moreover, the angular gap A between the front end 72a of each first fiber 70a, and each of the front ends 72b of the two second 70b fibers directly consecutive, is preferably of the order of 15 °. This value of about 15 ° considerably improves the collection of the optical signal. The performance of the probe is therefore substantially increased.

The invention also relates to a method of manufacturing the bimodal probe which has just been described. This method consists first of all to equip each shell 41 with its optical fibers 70a, 70b, inserting them laterally into their groove 76 of the inner surface of the shell. Then, these hulls with embedded optical means are reversibly assembled around the main body of the probe, as shown schematically in FIG. 9. This assembly is carried out by bringing the two shells closer to one another in a direction 94 orthogonal to the axis 4, around the main body 10, until clipping of the lugs 80 into the corresponding notches 82. Once the reversible assembly has been obtained, a biopsy tool 98 for taking a tissue sample in the suspect zone or zones may be mounted externally on the shells 41, also by clipping around the central portions 42, as shown in FIG. Of course, various modifications may be made by those skilled in the art to the invention which has just been described, by way of non-limiting example only.

Claims (17)

REVENDICATIONS1. Device (40) for bimodal diagnostic probe with optical and ultrasonic imaging, said probe being intended to comprise a main body (10) carrying at its front end at least one ultrasonic transducer (12), said device comprising a shell (41) extending in a longitudinal direction between a rear end and a front end intended to form at least partly the front end of said probe, said device also comprising illumination means (72a) mounted on said front end of the hull in such a way as to provide illumination outside the latter, as well as collection or detection means (72b) mounted on said front end of the shell so as to ensure the collection or detection of an optical signal produced externally to said shell, characterized in that said shell comprises fixing means (80, 82) for its reversible assembly around the main body (10) of the probe, with said illumination means and collection or detection means (72a, 72b) mounted on this shell. 2. Device according to claim 1, characterized in that said illumination means (72a) are associated with a first wiring (70a), in that said collection or detection means (72b) are associated with a second wiring ( 70b), and in that said first and second wirings (70a, 70b) run longitudinally along said shell, from said forward end of the shell, at least to its rear end. 3. Device according to claim 2, characterized in that said first wiring comprises at least a first optical fiber (70a) whose front end (72a), mounted on the front end of the shell, forms said illumination means . 4. Device according to claim 2 or claim 3, characterized in that said second wiring comprises at least a second optical fiber (70b) whose front end (72b), mounted on the front end of the shell, forms said means of collection. 5. Device according to any one of claims 2 to 4, characterized in that said first wiring comprises a plurality of first optical fibers (70a), each of the front ends (72a) forms illumination means, in that said second wiring comprises a plurality of second optical fibers (70b) each of whose front ends (72b) form collection means, and in that the front ends of the first and second optical fibers are inscribed on at least one curved line (90 ).30 6. Device according to claim 5, characterized in that the front ends (72a, 72b) of the first and second optical fibers (70a, 70b) are arranged alternately on a curved line (90). 7. Device according to claim 5 or claim 6, characterized in that the curved line (90) is an arc of a circle. 10 8. Device according to claim 7, characterized in that the angular difference between the front end (72a) of any first fiber (70a) and each of the front ends (72b) of the two second fibers (70b) directly consecutive is between 5 ° and 25 °, preferably between 10 and 20 °, and is even more preferably of the order of 15 °. 9. Device according to any one of the preceding claims, characterized in that said illumination means and said collection or detection means are flush with the outer surface (8) of the shell. 25 10. A bimodal optical and ultrasonic imaging probe (1), comprising a main body (10) carrying at its front end at least one ultrasonic transducer (12), said probe further comprising at least one device (40) according to Any one of the preceding claims, wherein the shell (41) carrying said illuminating means 23 (72a) and collecting or detecting means (72b) is reversibly assembled around said main body (10). 11. Probe according to claim 10, characterized in that it comprises two devices (40) according to any one of claims 1 to 9, with the two shells (41) arranged symmetrically in a plane passing through a longitudinal axis. (4) of the probe. 12. Probe according to claim 11, characterized in that the two shells (41) jointly form an envelope all around the main probe body (10), and in that at their front ends, these two shells define a filled space by said at least one ultrasonic transducer (12). 13. Probe according to claim 12, characterized in that it also comprises, at the interfaces (86) between the shells (41), a filling material of these interfaces. 14. Probe according to claim 10, characterized in that it comprises a single device (40) according to any one of claims 1 to 9, with a single shell extending over 360 ° about the longitudinal axis (4 ) of the probe. 15. Probe according to any one of claims 10 to 14, characterized in that it also comprises a handle (2) from which the main body (10) extends forward, and in that said handle (2) has one or more grooves (79) on its outer surface, receiving the first and second wirings (70a, 70b) from the rear end of the shell (41) of each device (40) according to the claim 2. 16. Probe according to any one of claims 10 to 15, characterized in that it is an endorectal or vaginal probe. 17. A method of manufacturing a bimodal probe (1) according to any one of claims 10 to 16, characterized in that it comprises the following steps. equipping the hull (41) of each device (40) with its illumination means and collection or detection means (72a, 72b); then - reversibly assembling each device (40) around the main body of the probe (10).